We are investigating cardiovascular (heart rate, blood pressure, and cardiac output), biochemical (plasma catecholamines, beta-endorphin), and psychological (pain, anxiety) responses to wisdom tooth extractions in patients with essential hypertension, normotensive controls, and normotensives with a family history of hypertension. Neural circulatory control mechanisms were studied in a ptient with recurrent vasodepressor syncope. Plasma and urinary catecholamines were measured during the normal human ovulatory cycle.